We visited Camilla Plum at Fuglebjerggaard just outside Copenhagen and she served us this delicious apple cake. She also added a pinch of ground star anise in the sugar mixture (with the cinnamon and cardamom).
1. Cream butter and brown sugar until sugar dissolves - about 5 minutes. Add eggs one at a time, beating well after each addition.
2. Sift flour with potato starch, baking powder and salt. Add to¬†batter just until mixed together.
3. Combine sugar with cinnamon and cardamom. Mix half with the apples and reserved the rest.
4. Butter a 10" or¬†11" springform pan generously. Add batter.¬†Press the apples into the batter firmly. Sprinkle remaining sugar over the top.
5. Bake in a preheated 350F oven¬†1 to¬†1 1/2¬†hours¬†(or longer) until the cake is cooked through - a toothpick inserted into the centre should come out dry and a meat thermometer should reach 185F. Serve with whipped cream.